<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>

    <style>
        h1 {
            background-color: red;
        }
        div {
            background-color: yellow;
        }
        p {
            background-color: black;
            color: white;
        }
    </style>
</head>
<body>
    <h1>css background实例</h1>
    <div>
        first line
        <p>first param</p>
        last  line
    </div>
</body>
</html>